How much effect is four pounds per wheel
- Thread starter Mid_Life_Crisis
- Start date
Thanks!
Dude..Flat out..If you reduce unsprung weight..and reduce rotational mass..your Response will be better..Period.
Its the same reason I just dropped over $2g's on a set of wheels for my Motocycle...For every ounce of rotational mass I can drop from the bikes wheels..Its like dropping 4x that weight from the sprung(non moving) part of the bike.
At speed..each once of weight I drop from my rotational mass will be like dropping 25lbs. at 100MPH....SO for me...Dropping just 20 oz. from my wheels would be like shedding 500lbs. at 100MPH.
Which is a hell of a difference.
Think of it this way...We buy lightweight flywheels why?
TO drop Rotational Mass from the engine...Guess what..your wheels are still rotational mass.
Connected to the Drivetrain.
Now...Not all wheels are created equal...two identically weighted wheels can react differenty depending on the weights distribution.
If the wheel drops the weight from the outer RIm shell area..vs losing it around the Hub..It will perform better than the wheel that dropped most of its weight at the hub.
It really is Physics man.
Dropping 4-5 lbs a wheel will take 8-10 Lbs. of rotational mass from your drivetrain which will help you out..Not to mention the fact that you drop apprx. 20 lbs from the cars sprug weight.
Its the same reason I just dropped over $2g's on a set of wheels for my Motocycle...For every ounce of rotational mass I can drop from the bikes wheels..Its like dropping 4x that weight from the sprung(non moving) part of the bike.
At speed..each once of weight I drop from my rotational mass will be like dropping 25lbs. at 100MPH....SO for me...Dropping just 20 oz. from my wheels would be like shedding 500lbs. at 100MPH.
Which is a hell of a difference.
Think of it this way...We buy lightweight flywheels why?
TO drop Rotational Mass from the engine...Guess what..your wheels are still rotational mass.
Connected to the Drivetrain.
Now...Not all wheels are created equal...two identically weighted wheels can react differenty depending on the weights distribution.
If the wheel drops the weight from the outer RIm shell area..vs losing it around the Hub..It will perform better than the wheel that dropped most of its weight at the hub.
It really is Physics man.
Dropping 4-5 lbs a wheel will take 8-10 Lbs. of rotational mass from your drivetrain which will help you out..Not to mention the fact that you drop apprx. 20 lbs from the cars sprug weight.
Don't get me wrong, I agree. but 4-5lbs a wheel is going to be more like 200lbs of unsprung weight. check the excel worksheet posted on the mazda6tech site.
OK..I just made a point of how it helps us on our bikes...and the fact that it will in fact help his performance.
I didnt read that spreadsheet..nor do I need to.
I know the effects of changing weight around.
The OP just couldn't beleive it would help...SO I was trying to show him how.
Dropping Rotational Mass Does in fact help.
Nuff said.
I don't think the agrument was rather or not it helped at all; but "how much" does it help and is it really worth the $$$?
From what I've gathered, to get some real improvement from the unsprung weight side of things, it would be alot more beneficial to get a set of light weight (14-16lbs) 17's vice 18's that weigh only 4lbs less per wheel. 17's are of course going to be a little less $$$ as well
From what I've gathered, to get some real improvement from the unsprung weight side of things, it would be alot more beneficial to get a set of light weight (14-16lbs) 17's vice 18's that weigh only 4lbs less per wheel. 17's are of course going to be a little less $$$ as well
Well thats a no brainer..If your purely going for Speed and performance..But who wants a tiny ugly whel ..No one....But a true race car...You have to have a Happy medium..a balance.I don't think the agrument was rather or not it helped at all; but "how much" does it help and is it really worth the $$$?
From what I've gathered, to get some real improvement from the unsprung weight side of things, it would be alot more beneficial to get a set of light weight (14-16lbs) 17's vice 18's that weigh only 4lbs less per wheel. 17's are of course going to be a little less $$$ as well
And Yes..If you want new wheels for the looks..and you can drop weight at the same time..yes..you its worth it...It has benefits of both worlds.
Performance and looks.
I don't think 17's would look all that bad with the right drop.
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- 2007 MS3
My dilemma is whether to buy a set of 23 pound wheels and Cobb springs now or buy 19 pound wheels now and have to wait for Christmas (or maybe next tax season) for the springs. I need to get rims for the summer tires I already have and can't use until I get 8" rims for them. Hence my question. Is the performance gain of the 4 pounds worth spending the summer without the springs? From what I can tell from that spread sheet, it appears that the gain from 4 pounds is not worth fussing over. Yes, there would be an improvement, and I might even notice it, but it wouldn't be enough to outweigh the handling improvement I'll get from the springs. I'm going to get the heavier rims and springs now.
Thank you all for the feedback.
Thank you all for the feedback.
dude, you want the 19 lbs wheels, hands down.
Get what you would rather have. On a street car, the difference isn't enough to warrant "changing plans".
If it was me, I'd get the springs and 23lb wheels. This is coming from someone with 18lb wheels.
If you want to get right down to it, shop for the lightest tires. They have more of an affect on rotational mass as they are furthest from the hub. Edge racing lists tire weights.
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- 2007 MS3
Good advice, unfortunately I already have the tires. RT615s in 225/40/18reinforced are half pound heavier than the stockers. Essentially I'm shopping for rims for those tires. They will fit on 7.5 minimum, but wider is better according to Falken's site, so I'm going with 8.0 as they will fit the car.
Swamp, you are a true testament to genius and insanity being separated by a thin line. Thank you for the no b.s. answer.
Thanks to the rest who tried to help out as well. I know what to do now. I'm actually pleased, because I like the look of the heavier rim better anyway.
2.0t03speed
Member
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- 08.5 CWP Speed 3
hmmm im dropping tire and wheel weight i guess i will see what happens
2.0t03speed
Member
- :
- 08.5 CWP Speed 3
im gong from 48lbs with stock msp rims w/ 215-45-17 avid h4's to my enkei evo 5's w/ 215-40-17 Hankook Ventus Rs2. i should see aout a 9 pound difference per wheel. id like to think 36 pounds of rotational mass taken off would make a difference
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- 2007 MS3
The lighter ones are Rota P1 delivered with all the necessary goodies for $750.
The heavier set are Sport Edition F10. I found someone in the forum who has had the brand and said they held up well. The offset on these is perfect for this car with an 8 inch rim. I know everybody (except Swamp who went bronze) is putting black rims on True Reds, but I really like the look of the machined face with everything else blacked out. These are at Tire Rack delivered with all the goodies for $601.
